The three Malakie boys comes to town and bust up the saloon. Lucas McCain and Marshal Micah Torrance stop them, but in the course of doing so, one of the boys shoots and kills his own brother. That doesn't stop them from blaming Lucas however and when their father Daniel Malakie arrives, he breaks his two surviving sons out of jail intent on getting even. They ambush someone they think is Lucas but get it wrong and Lucas and Micah hunt them down.
Al Walker, a notorious gunfighter, has come to North Fork to die. He has an incurable illness and, since he had once been a wealthy and prominent lawyer, believes he owes it to his family to have his death certificate read "natural causes" instead of "killed in gunfight". However, the Porter brothers--a gang of vicious killers and bank robbers--have followed him to town and plan to take their revenge on Walker for killing their brother, and they'll stop at nothing and no one in order to do it.
Town ne'er-do-well Brett Conway finds out that a couple who moved near North Fork and soon fell sick are actually ill with highly contagious and potentially fatal yellow fever. Knowing that Lucas was the person who initially discovered the couple, Conway threatens to spread the news of their condition to the entire town, thereby causing a panic, unless Lucas buys his silence.
An outlaw gang kidnaps Micah and threatens to kill him unless their leader is released from jail. Lucas must decide whether to turn loose the notorious killer or face the possibility of the murder of his friend Micah.
In their search for a wealthy man's long-lost son, private detectives arrive in North Fork. Upon seeing Mark, they decide that since they can't find the real boy and their client has never actually seen his son, Mark will suffice.
Stablehand Colly Vane, while out hunting, gets the drop on notorious wanted gunfighter The Domino Kid, and is forced to shoot him. When Colly brings the Kid's body into town to claim the reward, it's noticed that the Kid had been shot in the back. Instead of being hailed as a hero, Colly becomes the object of the townspeoples' derision for having shot the Kid in the back, is fired from his job and evicted from his house. To make matters worse, three gunfighters who were the Kid's friends come to town looking for him, and when they find out he's dead, set out to find ...
While North Fork excitedly awaits the arrival of a new preacher, Mark uncovers evidence that suggests the new parson is not only not a preacher, but may in face be planning to use the occasion to rob the town bank.
Marge Crandell is a headstrong young girl who doesn't like to be told what to do, not by her father or by Doug Carter, the man who loves her. Doug is hot tempered and ready to fight any man who gets too close to Marge. He has just such a fight with Fred Tate who had been bothering Marge. Instead of being grateful Marge walks off with the drummer Rodney Quentin. Later when Lucas discovers her body both Quentin and Tate emerge as possible suspects.
Gabe Fenway, a sharecropper for local landlord Preston, plans to run his quarterhorse Sapphire in a local horse race. Mark also plans to race his horse, Blueboy, in the race. Preston, who wants to keep all of Fenway's crops, believes Mark's horse can beat Fenway's and tricks Fenway into betting his crop against Preston's $1000 that Mark will win. And to make sure that Mark wins, Preston has a plan to make sure that Fenway doesn't make it to the race.
Lucas hires a new ranch hand, then learns that the man had just been released from prison for manslaughter. He believes the man has turned over a new leaf and wants to start a new life, but his--and the townspeoples'--suspicions are aroused when a local rancher is murdered during a robbery.
While in town one day, Lucas runs into Tom Benton, an old friend from his days in the army. Benton seems to have fallen on hard times, though, as he's drinking heavily and winds up shooting up the saloon and getting arrested by Micah. Lucas bails him out, against Benton's protests, but it turns out that Benton has his own reasons for wanting to stay in jail.
Nora Sanford, an old flame of Lucas' who came from a wealthy family, arrives in town, ill and penniless. When Lucas hears of her condition, he goes to see her and help nurse her back to health. It turns out that her recently deceased husband had spent all her money, and she had heard that Lucas had also been recently widowed, and in desperation decided to come to North Fork to see him. What Lucas doesn't know, however, is that she didn't come to town alone, and her plans for Lucas aren't quite what he thinks they are.